1. Field of the Invention
The invention relates to a tilt switch, more particularly to a sandwich-type tilt switch that uses angular changes to open or close a circuit.
2. Description of the Related Art
Referring to FIGS. 1 and 2, a tilt switch 1, as disclosed in Taiwanese Patent No. M409517, includes an insulated housing 11, a cover 12 that mates with the insulated housing 11 and that cooperates with the same to define an accommodation chamber 10, four terminals 13, and a ball 14 disposed in the accommodation chamber 10. The insulated housing 11 has a plurality of engaging pegs 111 projecting from an upper surface thereof, and a plurality of accommodating grooves 112 and a plurality of pinholes 113 formed in a lower wall of the insulated housing 11 that allow spatial communication between the accommodation chamber 10 and an exterior of the insulated housing 11. The cover 12 has a plurality of openings 121 for extension of the respective engaging pegs 111 therethrough. Each of the terminals 13 has a contact portion 131 that extends through a respective accommodating groove 112 into the accommodation chamber 10, and a welding portion 132 exposed to the exterior of the insulated housing 11.
This structure allows the ball 14 to roll between a closed circuit state, in which the ball 14 simultaneously bridges any two of the contact portions 131, and an open circuit state, in which the ball does not simultaneously bridge two of the contact portions 131. Hence, an ON/OFF effect of the tilt switch 1 can be achieved.
The pin holes 113 respectively accommodating a plurality of positioning pegs 15 are formed in the lower wall of the insulated housing 11 of the tilt switch 1 when forming the insulated housing 11 by injection molding. To facilitate the injection molding of the insulated housing 11, the positioning pins 15 are disposed to respectively abut against the terminals 13 to stabilize the terminals 13. However, gaps that permit penetration of moisture are formed between the pin holes 113 and the respective receiving grooves 112. Further, because the positioning pins 15 merely abut against the terminals 13 and do not secure the positions of the terminals 13, the terminals 13 may easily shift during the injection molding process, thereby causing formation anomalies that may reduce assembly precision.